The present invention has utility in packaging electronic equipment, particularly in data processing systems where signal transmission may occur at very high clock speeds, for example, above 100 MHz.
It is known to interconnect electronic printed circuit boards in a card cage or other form of chassis, utilizing, for example, coaxial and multi-coaxial cable, ribbon cable, fiber optic cable, and the like. In this way, power, data, and control signals may be conducted between circuit boards.
In data processing systems wherein signals are transmitted at very high clock speeds it is desirable to have cabling which provides a matched signal length. That is, two or more signals generated simultaneously into a cable should arrive simultaneously at the other end of the cable. The term "signal skew", as used hereinafter, refers to the extent one such signal arrives ahead of another through a transmission medium. Because of the very high speed operation of the logic circuits in such a data processing system, incorrect logic states can result if signals are delayed relative to other signals.
It is also desirable to provide a cable which is substantially immune from noise. In addition, the cable should have minimal signal attenuation.
In dense electronic packaging configurations, utilizing high speed logic, wherein a significant amount of heat may be generated, it is also desirable to minimize cable interconnections which would block the flow of a coolant fluid, such as air, through the packaging structure.